I took a look at the scattering noise we see in all lock since last night .

I computed the band-limited RMS between 20 ans 120 Hz, and this is a good indicator of the scattering noise level. Then I looked at correlations with all suspension motions (using M0 and M1 signals, as Keita did for the OMC).

So I'm able to reconstruct the noise variation over time, using a linear combination of all the suspension signals and their squared values. However, I'm not able to pick point one single mirror which is moving more, as shown in the ranking of the most important channels for the BLRMS reconstruction.

I compared the suspension motion spectra from tonight (GPS 1123422219) and few days ago (GPS 1123077617). The most relevant difference is that all test masses YAW motion have now a large bump at 3 Hz. ITMY also has large lines at 0.45 and 0.63 Hz. Finally ETMY pitch shows a large line at 6 Hz and some excess noise above that frequency.

Not sure if all of this is really relevant...